Surgical opening of vagina to help urination? Others?

I'm 80 years old and having difficulty urinating. The vaginal opening has closed over. My gynourologist wanted to pass a catheter but was unable to "find" the opening of my urethera. She feels that opening the vagina surgically will help me to pass my urine. Have any others had this situation? What was the results? I also have lichen planus there that is very painful on a daily basis, especially when I pee. She is waiting on me to schedule the surgery. HELP!!